-664560

Appears in sequences

• a(n) = 1*2*3*4*5*6 - 7*8*9*10*11*12 + 13*14*15*16*17*18 - ... + (up to n).at n=11A319546
• a(n) = 6*5*4*3*2*1 - 12*11*10*9*8*7 + 18*17*16*15*14*13 - 24*23*22*21*20*19 + ... - (up to the n-th term).at n=11A319889